Coronavirus Symptoms Usually Take 5 Days To Appear, Study Says Coronavirus symptoms usually take about five days to appear after exposure, and almost always emerge within two weeks — confirming that a 14-day quarantine is appropriate, according to a new study.

    The study, conducted by the Johns Hopkins Bloomberg School of Public Health, reveals that the median incubation period for SARS-CoV-2 — the virus causing the respiratory illness COVID-19 — is 5.1 days.

    Additionally, about 97.5 percent of people who develop symptoms of the deadly bug will do so within 11.5 days of exposure, the study revealed, according to a press release.

    The findings suggest that the 14-day quarantine period used by the CDC is a reasonable period of time. For every 10,000 individuals, only about 101 would develop symptoms after being released from a 14-day quarantine, the results show.

    The researchers analyzed 181 cases from China and other countries that were detected prior to Feb. 24 — the early stages of the outbreak.

    At that time, most of the cases involved travel to or from Wuhan, China, where the outbreak emerged in December — allowing researchers to estimate the “time of exposure” by determining when a person was in that city, CNN reported.

    “We have sort of a narrow window at the beginning of the epidemic to really tease out what’s going,” Justin Lessler, an associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health, told the network. “If it’s everywhere, you don’t know where people got infected.”

    The findings, he said, also indicate that symptomatic screening — including temperature checks at an airport — might be missing people who recently contracted the virus.

    “If somebody is in their incubation period, that is the window when somebody who’s already been infected can walk into the country and not be detected by symptom-based surveillance,” Lessler told CNN.

    The results of the study were published in the Annals of Internal Medicine Monday.